In the study, Professor Muttarak (University of East Anglia, UK, and the International Institute for Applied Systems Analysis, Austria) compared data collected between 1997 and 2015. She analysed people’s body mass index (BMI), as well as whether people reported that they perceived themselves to be (a) about the right weight, (b) too heavy, (c) too light, or (d) not sure. In addition, participants were asked to report whether they were (a) currently trying to lose weight, (b) trying to gain weight, or (c) not trying to change weight. The results showed that, from 1997 to 2015, an increased proportion of adults classified according to their BMI as “overweight” or “obese” perceived themselves to be “about the right weight,” rather than “too heavy.”

Sloppy science, peer review, and journalism

Muttarak's research merely looked at the associations between people’s BMI, their self-perception of their body weight, and whether they reported that they were trying to lose weight. The research did not – in any way – investigate or even assess whether the body-positive movement has had any impact on people’s BMI, their perception of their body weight, or their attempts to lose weight. To draw such conclusions, experimental or longitudinal research would be necessary, for example wherein people’s exposure to body-positive media imagery is measured across time, along with their body weight and other outcomes. The fact that journalists have concluded that the “body-positive movement is probably contributing to the obesity crisis” is unfounded, not to mention that the study did not even investigate this question.

It is also concerning that Muttarak hints at this relationship in her article. For example, she states that the availability of “plus-size” clothing “may have indeed contributed to the normalization of stigma associated with overweight and obesity” (p. 1125) and that, while the body-positive movement may help “reduce stigmatization of larger-sized bodies, it can potentially undermine the recognition of being overweight and its health consequences” (p. 1125). Yet, no solid evidence is given to support her statements and, where references to other research are provided, these are either unrelated to her claims or have misinterpreted the referenced study’s findings. Such misleading writing is careless and unacceptable in a scientific journal, and raises serious concerns about its peer review process.

The take-home message

This research cannot be used to support the claim that the body-positive movement is contributing to “overweight” or “obesity.” The study did not test this question, and the data cannot be used to answer it. The reviewers at Obesity should have picked up on this, and journalists should have done their homework. Sloppiness in science, peer review, and journalism, is unacceptable, especially when so much awareness has been raised about these issues in recent years. Most people do not have the time or resources to access and read the scientific articles behind the news headlines. It is therefore the job of scholars, reviewers, and journalists, to get the facts straight, and not spread false claims.

It is also worth mentioning that there are several other concerns with Muttarak’s research and her interpretation of the data. For example, a major assumption behind her research is that recognition of being “overweight” or “obese” is necessary to begin leading a “healthier” lifestyle. This is, in fact, untrue: For further explanation and discussion on this topic, check out Professor Tiffany Stewarts’ prompt commentary in Obesity.

References

Muttarak, R. (2018). Normalization of plus size and the danger of unseen overweight and obesity in England. Obesity, 26, 1125-1129.

The study tries to explain the possible reasons behind the rise in weight misperception among men and women in England over the period 1997-2015, and normalisation of being overweight and obesity is one theory raised. While there is no statistical evidence on the link between body positivity and the rise in weight misperception, there is no evidence so far to rule out this hypothesis either. The aim of the article is to highlight the rising trend in weight misperception and the social inequalities associated with it. The key finding that overweight and obese individuals who underestimated their weight status are less likely to try to lose weight emphasises that weight misperception is worrying, especially in the UK where two-thirds of adults are overweight or obese. The suggestion on the potential link with body positivity, on the other hand, hopes to inspire future research to test this hypothesis.

I disagree that the study "tries to explain the possible reasons behind the rise in weight misperception." I would say that the study investigated potential changes in perceptions of one's body weight across time. Full stop.

To be able to test anything about the possible reasons behind weight misperception, you would have need to directly test any proposed causal factors, such as exposure to body-positive media or purchasing "plus-size" fashion. Further, you would have needed to assess these relationships across time, or in the context of a randomised-controlled trial.

The fact that there is no evidence to rule out the hypothesis that body positivity contributes to a rise in weight misperception is no license to be able to conclude, or suggest, that it does. Not having any evidence to support something does not make it true.

It is also debatable whether underestimation of one's weight status should be as worrying as you suggest it is. Indeed, in Professor Stewart's commentary in Obesity, evidence is provided for the fact that identifying oneself as overweight or obese is, counterintuitively, associated with future weight gain. Professor Kersbergen also notes (see her Twitter feed) that you have misrepresented her review. Indeed, her review showed that people who perceive themselves as overweight are more likely to try to lose weight. However, as Professor Kersbergen notes, "what the author failed to mention is that this doesn't result in weight loss. In fact, perceiving yourself to be overweight is related to weight gain overtime."

I hope that you will be more careful in any future reporting of your research, and when communicating your findings to the media. As I mentioned, most people do not have the time or resources to access and read the scientific articles behind the news headlines. It is therefore our job as scholars - as well as the job of reviewers and journalists - to get the facts straight, and not spread false claims.

I reported on Dr. Muttarak's study and understood the study to be a preliminary one. I also understood that she was putting forward a possible hypothesis for further research. I understood that the relationship between increased acceptance of overweight/obesity and misperception of weight is a correlation. Preliminary studies typically do not look for the causal relationship; that is for future research.

I am also aware that Dr. Muttarak's work joins a growing body of research on weight perception, and how our perception of our own weight and the weight of others (even our own children) can be skewed by many behavioural and societal factors. Her work is not the first to wonder about the possible detrimental effects of body positivity.

In a world where a large and ever-increasing percentage of the population is suffering due to being overweight and obese (the stats are very clear on the health risks), and where an increasing number of small children and youth are also struggling with being overweight and obese, we absolutely have to find ways to address the problem. This includes looking at all possible contributing factors, including the movements in society that, on their surface, might seem innocuous or even wholly positive.

Here is a quote from Professor Kersbergen's review:

"We examined peer‐reviewed literature published between 1991 and 2017 and found strong evidence to suggest perceived overweight was associated with a higher likelihood of trying to lose weight and moderate evidence to suggest perceived overweight was associated with greater use of both healthy and unhealthy weight control strategies. However, those weight loss attempts and strategies did not appear to be translated into healthy weight‐related behaviours. ... The most consistent evidence to emerge from this review was that perceived overweight was associated with attempting to lose weight. This was the case regardless of participant weight status, age group and gender."

The research is not yet at the level to tease apart the causal factors for why they are gaining more weight even after trying to lose weight. It's also important to note that "Half of included studies were conducted on adolescent samples or a combination of children and adolescents, with the remainder on adults or a combination of adults and other ages, or only young adults (aged 18–25)."

For anyone who has lost weight on purpose, it is done because of a perception of being at a weight that the individual believes to be not ideal and/or unhealthy. This weight loss, to be permanent, requires an adjustment on many levels, with many experts saying that it does not require a mere diet and exercise plan, but a permanent lifestyle change. Without the proper societal, familial, and medical supports, said lifestyle changes are close to impossible.

And what may be a mediating factor for those who are unable to lose weight, is overeating as food addiction. See "Food addiction as a new piece of the obesity framework" by Jose Manuel Lerma-Cabrera et al.

As with any addiction, simply knowing there is a problem is usually insufficient for making lasting changes to reverse the problem.

And I want to make it clear that I am not suggesting that all overweight or obese people are addicted to food, since I know that there are many other factors at play, including systemic problems in the food industry, unaddressed health issues, and unaddressed socioeconomic inequalities, etc. But the research indicating that a significant percentage of obese individuals may suffer from food addiction is convincing and should not be ignored.

Other colleagues have commented on the issues you have raised concerning weight misperception and its relation to weight gain and health behaviours (see, e.g., Professor Tiffany Stewart's corresponding Commentary in the same issue of Obesity). The focus of my blog article is specifically on the claim that the body-positive movement is contributing to the "obesity crisis."

What I find perplexing is that this study is (still) perceived to have tested the relationship between the body-positive movement and weight misperception. You mentioned that you understood that the "relationship between acceptance of overweight/obesity and misperception of weight is a correlation." Yet, Dr Muttarak's research only looked at changes in weight misperception across time. Nothing relating to acceptance of overweight/obesity, nor the body-positive movement has been assessed. Yes, correlation is an important first step in the scientific process, but none such correlations were tested in Dr Muttarak's research.

In a similar vein, you mention that it is necessary to look at any societal movements that could contribute to obesity/overweight. Again, this study did not directly test the relationship or impact of any societal movements on contributions to obesity/overweight.

What I find problematic, with regard to the body image aspect of this discussion, is that the paper and your press release suggest that there is evidence (from this research) to point toward the causal relationship between the body-positive movement and obesity/overweight. In fact, the very title of your press release makes this claim: "Normalisation of ‘plus-size’ risks hidden danger of obesity." This is what I referred to as the "sloppy" aspect. Most people who read your press release will not have the time to access, read, and understand the scientific research behind your headline, and will thus go with the assumption that science has indeed discovered this relation. Again, as I stated, this is untrue.

I understand some of your concerns and I appreciate your taking the time to address them. To clarify, I did not write the press release, but I did receive the original press release through AlphaGalileo.

A great deal of research that I read includes the thoughts of the researchers regarding what may be going on or contributing to a particular phenomenon. That is how I read Muttarak's article, but I realize that not everyone will read it this way.

I do see now that the pervasiveness of body positivity and its effects were assumed, which is evident in places where the language in the article is unclear. Yet I do think that it is an intriguing area for further research, and I am hopeful that the dialogue about the topic will become more open. I see a lot of anger and "us versus them" communication whenever the topic of obesity and/or body positivity comes up. This is something I hope we, as a culture, can move beyond.